While fishing you will sometimes fish up junk. Junk acts just like fish (swims around, bites at your lure), but costs
money to dispose of. Each piece of junk costs 80 bells to recycle. The various pieces of junk are: A boot, A can, A tire

You will also find shells scattered along the beach. Early in the game, these are a quick source of bells. Later, their
value is generally too low to bother collecting.